A source tells HollywoodLife, "Brad’s name has come up many times, it’s just a matter of what his other commitments are.

"It’s the show everyone wants to be on, because the writing and the roles are just so exquisite and complex. Brad has tight relations with HBO — he teamed up withRyan Murphy last year to produce the HBO movieThe Normal Heart. I know everyone would be thrilled to have him onboard."

Pitt has played a detective investigating grisly crimes before, teaming up with Morgan Freeman in the thriller Se7en in 1995.

McConaughey's role is tipped to win a Best Actor Emmy and make him the only male actor to win the award and the Oscar for Best Actor in the same year. Perhaps the producers won't have to reach out to stars much longer.